2. Model Definition

1. 51304718: Base model for 16-channel non-isolated HART analog output FTA

2. -200: Medium heavy-duty reinforced PCB protection grade

   • Multi-layer medium-thick reinforced full-board conformal coating with outstanding resistance to high humidity, heavy dust and mild-moderate corrosive chemical vapors

   • Upgraded high-energy composite bidirectional TVS surge stack, higher transient withstand energy than -175/-125/-100

   • Three-stage symmetrical cascaded RC differential EMI filter, precisely tuned for extreme high-noise zones with massive VFD clusters and large motor control centers, no attenuation to HART carrier signal

   • Global common ground bus for all 16 channels, no independent galvanic isolation barriers between loops

   • Oversized reinforced flyback freewheeling diode arrays for complete dissipation of large back-EMF spikes generated by heavy inductive actuator coils

   • Ultra-precision tight-tolerance series damping resistors for perfectly uniform full-range 4–20mA linear stroke response across all 16 channels

   • Extra-wide thickened plastic channel baffles to eliminate inter-channel analog leakage and HART signal crosstalk

3. Technical Specifications

1. Channel Count: 16 common-ground output channels, no per-channel galvanic isolation

2. Compatible Field Devices

   • Two-wire HART smart valve positioners, heavy-duty electro-pneumatic HART I/P transducers, linear/rotary HART modulating actuators

   • Backward compatible with conventional non-HART 4–20mA pneumatic positioners and standard I/P converters

3. FTA Structure: Passive non-isolated termination board with no internal power supply; integrated per-channel HART coupling, three-stage symmetrical differential filtering, high-energy surge protection and heavy inductive kickback suppression

4. PCB Protection: Multi-layer medium-thick reinforced conformal coating; flammability UL94 V0

5. Terminal Type: Compression screw terminals, fit solid/stranded copper wire up to 14 AWG; each channel has independent Ch+ / Loop– terminal pair sharing unified global ground bus

6. Form Factor: Standard B-size footprint, snap-on installation for 35 mm standard DIN rails

7. Operating Ambient: 0℃ ~ +60℃ indoor control cabinet; humidity, dust and mild-moderate corrosion tolerance surpasses -175 and lower grades; not certified for continuous salt fog exposure (select -325/-375 ultra-heavy-duty grades for coastal/offshore salt fog environments)

8. Circuit Architecture Parameters

   • Three-stage symmetrical low-pass differential filtering, calibrated to suppress severe industrial EMI without distorting HART waveform or analog 4–20mA drive signal

   • Composite high-energy bidirectional TVS stack suppresses positive/negative transient high voltage on every shared-ground output loop

   • Shared common ground design; ground potential differences between field and DCS trigger valve stroke drift and unstable HART communication handshake

   • Ultra-tight tolerance damping resistors fully eliminate valve hunting and stabilize full 4–20mA linear output performance

   • Oversized flyback diodes rapidly absorb severe back-EMF energy from large inductive actuator coils

   • Extra-thick baffles fully block inter-channel analog bleed and cross-channel HART signal interference

9. Redundancy Support: Fully compatible with primary/standby redundant non-isolated HART AO IOP; hot-swap FTA replacement allowed without process shutdown

10. Approximate Unit Weight: 0.360 kg

4. Interface & Communication Configuration

1. Inner IOP Connection: Locking heavy-duty flat ribbon cable directly mates to non-isolated HART AO IOP pin headers. Reinforced multi-point cable strain relief prevents pin header deformation or fracture under sustained tension of long multi-core field control wiring harnesses.

2. Field Outer Terminals: Independent Ch+ / Loop– terminals for each two-wire actuator loop; all loops share one unified ground bus aligned with DCS control ground potential.

3. Signal Mechanism: 4–20mA DC analog drive signals overlaid with FSK HART digital signals via frequency division; low-distortion passive HART coupling integrated per channel circuit.

4. HART Access: No dedicated auxiliary communication port; handheld HART communicator clamps directly across Ch+ and Loop– field terminals for commissioning, calibration and diagnostic data reading.

5. Core Functions

1. Common-ground mixed HART/standard actuator drive: Cost-effective single-ground layout supporting mixed deployment of HART smart actuators and conventional non-HART 4–20mA loads in one cabinet.

2. Three-stage symmetrical heavy EMI noise rejection: Suppresses intense electromagnetic interference from large VFD systems, MCCs and medium-voltage switchgear to eliminate valve hunting, setpoint fluctuation and frequent HART communication retries.

3. High-energy surge & short-circuit fault protection: Withstands lightning-induced line transients, equipment startup surges and field short-circuit high voltage to protect sensitive costly IOP output power semiconductors and field actuators.

4. Heavy-duty uniform inductive load safeguarding: Oversized flyback diodes evenly protect all channels from coil back-EMF damage for long-term stable operation.

5. Consistent channel linearity & HART synchronization: Ultra-precision matched passive components deliver identical valve stroke response and stable HART handshake across all 16 channels to reduce bulk calibration workload.

6. Redundant hot-swappable operation: Seamlessly follows primary/standby IOP switching logic; single-channel disconnection and troubleshooting do not impact operation of remaining 15 control loops.

6. Application Scenarios

Applicable Industries

Typical Control Loops

1. Emergency safety shutoff system HART smart valve positioners

2. High-volume heavy-duty process throttle HART modulating actuators

3. Large furnace draft air damper HART I/P transducers

4. Process blending control valve smart HART positioners

5. Pressure reduction modulating HART actuators

   Ideal for single-ground plant layouts, VFD-dense process areas, cabinets with persistent high humidity and heavy dust accumulation, and atmospheres containing mild-moderate acidic/alkaline volatile vapors. Not suitable for offshore platforms or coastal sites with continuous salt fog exposure.

7. Wiring Standards

1. Two-wire actuator wiring: Actuator positive → FTA Ch+, actuator negative → FTA Loop– (shared ground bus); reversed polarity generates measurable valve stroke offset and degraded HART waveform integrity.

2. Cable specification: Shielded twisted-pair instrument cable for all field wiring runs; cable shield grounded solely at DCS cabinet FTA side with field equipment end ungrounded to fully suppress ground loop noise.

3. Power cable segregation: Physically separate HART analog control cables from high-voltage AC power, MCC and VFD output wiring to minimize capacitive and inductive EMI coupling interference.

8. Incompatible Hardware